Security readout for executives and security teams
Plain-English summary
This flaw lets an unauthenticated person query a Metasys ADS/ADX/OAS web API and list users. That exposes account information which can support later targeting, but the cited CVSS impact is confidentiality only. It affects Metasys 10 before 10.1.6 and 11 before 11.0.2.
Executive priority
Treat this as a medium-priority remediation for building-management environments. It is not described as direct system takeover, but exposed user data can materially improve an attacker’s ability to target operational technology accounts.
Technical view
CVE-2021-36200 is a CWE-306 missing-authentication issue in Johnson Controls Metasys ADS/ADX/OAS with MUI. Network access, low complexity, no privileges, and no user interaction are required. The documented impact is user enumeration through the web API; no integrity or availability impact is stated.
Likely exposure
Organizations running Metasys ADS/ADX/OAS 10 before 10.1.6 or 11 before 11.0.2 are in scope, especially where the web API is reachable from user networks, vendor access paths, or the internet.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The issue is still operationally relevant because unauthenticated user enumeration can help attackers map valid accounts for follow-on access attempts.
Researcher notes
Do not assume broader product impact beyond Metasys ADS/ADX/OAS with MUI. The provided sources describe user enumeration only, not code execution, privilege escalation, or confirmed exploitation. Validation should focus on version, API exposure, and authentication enforcement.
Mitigation direction
- Upgrade Metasys 10 deployments to 10.1.6 or later where applicable.
- Upgrade Metasys 11 deployments to 11.0.2 or later where applicable.
- Review Johnson Controls security advisories for supported upgrade paths and compensating controls.
- Restrict Metasys web API access to trusted management networks.
- Monitor exposed Metasys services for unauthenticated enumeration attempts.
Validation and detection
- Inventory all ADS, ADX, and OAS servers and record installed Metasys versions.
- Confirm whether each server uses MUI and exposes the relevant web API.
- Verify vulnerable versions are upgraded or have vendor-approved mitigations applied.
- Review access controls limiting API reachability to authorized network segments.
- Check logs for unusual unauthenticated API activity or repeated user-listing patterns.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-306: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-36200 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.johnsoncontrols.com/cyber-solutions/security-advisoriesCVE reference · x_refsource_CONFIRM
- ICS-CERT AdvisoryCVE reference · third-party-advisory, x_refsource_CERT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authentication for Critical Function
Missing Authentication for Critical Function represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.